Constructive criticism sought

[shaunf]

So, I'm sure most of you have heard the now infamous clips.

To be honest, that incident has rattled my confidence a bit. I know that what I have to ask is quite difficult, considering the flawed recording method and subsequent quality. I also want to mention that my amp is fitted with a Hall VVR, which I have noticed with this set to lower levels, does make the amp sound buzzy, particularly if you don't adjust the volume control down a bit to what you would normally set it on. I thought I had that buzziness dialed out with the VVR on about 1/3 when I made that clip, and to be honest, the amp didn't sound buzzy to me in the same room.

So, what I would like to know from those of you who are willing to share your honest opinions, is what you think of my amp. Particularly I'm interested in others opinions who also have a VVR in their amp, I'm interested to hear from people if they think my amp sounds like an express or not, I'd like to know if you think it sounds buzzy or if you think its just the recording, and most of all I'd like to know if you think it needs further work or tweaking, and if so what aspects do you think I should look at.

When I built it, I didn't install any grid resistors since it has been stable from the beginning. Also, when I biased it up, I just did it to 70 percent of max plate dissipation and left it at that without trying any other values. Is this something worth looking at?

Despite what Garlin seemed to think, I am in fact very much open to constructive criticism, and came here and built my amp to learn as much as possible. This amp was my first ever scratch build, and I'm far from thinking I know it all, or even really know anything at all when it comes to these amps. I do not offend easily and so you don't have to spare my feelings. At the end of the day, I'm here for the conversations with like minded people, for the education and to get my amp to sound as good as possible, and so if its not done yet, I'm very happen to carry on tinkering.

Thanks to all of you who have helped me get this far.

Regards,
Shaun

[Bob S]

Hi Shaun - it sounds very much like an Express to me.
The only advice I can offer is, when it you are happy with the sound, it's done.
And for a first scratch build, be very happy.
Once again - a sincere Well Done!

[Colossal]

There is a very big difference between judging an amp by standing in front of it while someone is playing and dismissing it outright based on a one-take primitive recording that has no optimization whatsoever. So don't let that guy get to you. If you spent big money at your local studio and recorded your amp professionally, I'm sure it would sound very much like a Trainwreck and very much more like it does when you are standing in front of it.

Whatever the amp's lineage, if it sounds good to you, then it is. WhoTF cares what anybody else thinks.

[Richie]

I've installed quite a few VVRs in wreck type amps. If its installed right, there isn't any buzz sound. Like about anything, if its not installed right, or depending on how its installed, what vlotages its changing or not.
Or if you lower the voltage in the preamp, and do not have the 1M and added cap on the grids of the tube the amp can get buzzy, splattery, lose signal type sound,sputter etc.
If the lead dress is not good, or mounting position,you can have buzz,and noise when turning the control. All of which, can be cured if done correctly.
And most any amp useing whatever type attenuator, the sound will change between full blast, to the softest level.

As for recording, have you listened to Garlins videos/tone/ playing?
Some may not agree that his clips/tone /Airbloom amps/playing are as good as he thinks they are.
Over the years recording gizmos have got much better.
I wish we had some of those that are out today,and used them back when we tried to capture some of the amps sound.
If you went on what the camcorder files sounded like, you'd probably agree it pretty much sucked. You still might get an idea of how it reacted. But it never sounded like that in the room.

Same with some phone recordings. They just don't do an amp justice.
Many times in studio recordings,they can also be doctored,like added reverb when an amp doesn't have reverb. Or whatever. And some of us, me included, just don't have recording gear,fancy mics, etc,or the talent some have of capturing the sound.

And the last thing is, the part that no one can get unless your in the room,plugged into the amp,hearing it through the speakers,is how the amp reacts to your playing/guitar. Each player has a different feel, hard handed or soft. And to really compare amps, you need to have them side by side. Plug in from one to the next, using same guitar/speakers/room/ etc, then you can really tell or hear the differnces.

And no matter, just think of the youtube dislikes. i don't care how good something is, song,amp whatever, you'll always have someone hit the dislike button..

[passfan]

Don't let a "cork sniffer" disuade you from doing something you like to do. We all started out with the "first amp". Yours doesn't sound bad at all. Screw garfield.

[shaunf]

Thanks very much for the reassurance guys, very much appreciated!

Richie, thanks for weighing in on this, and I'm very interested in what you say about the 1meg resistor and added cap on the preamp grids and their affect on tone. For some reason I was under the impression that these were only required to block DC voltage leaking back to the guitar pots at low VVR levels, and not to do with tone.

I actually had the cap and resistor installed initially but for some reason I had a strange issue of scratchy guitar pots, but at any level of the VVR, even max. While I was troubleshooting, I measured for DC between the grid pin of v1 and the cap, and there was a tiny amount of voltage, however on the other side of the cap, closest to the input jack, I had over 1v present. Any idea what could cause this, and why a cap would show more voltage after it then before it? I ended up removing the cap and 1meg between the input and v1, and just left the other 1m on the input jack in place, and the problem went away. Now I only have a very small amount of voltage leaking back to the input and only at very low VVR levels, like from 1/3 and down. Do you think this could have been a leaky cap?

I did later find that 500pf silver mica cap after the first 2 orange drop coupling caps close to v1 was leaky, and ended up replacing it, but I haven't tried the caps and resistors on the grids again.

[Reeltarded]

Don't worry. Your amp sounds great and it operates wonderfully between clean and dirty.

Do get that voltage off the input. If you don't have the same value replacement, use anything larger.

Add small grid resistors to remove ultrasonic stuff. 10k-68k or larger even. I start big and keep relaxing it down to what works without making a tonal difference.

[shaunf]

Richie, I owe you big time!

<---- me, and you couldn't wipe the smile off my face if you tried!

I just spent 15 minutes installing some caps and 1meg resistors between the V1 grids and the volume control and input jack. I can't believe the difference. Amp is transformed. The amp has great tone, even at very low VVR levels, the sound is fuller, and the bottom end has tightened up significantly. Best of all, there is no buzziness, even at bedroom levels.

Just a question about the caps in these positions. I used some Vishay MKT 1813's which are metalized polyester caps. I originally bought them to try as coupling caps in my Marshall, but didn't like the graininess they added to the sound. I used them because they are the physically smallest 0.1uf caps I had, which made installing them at the tube sockets easier, but I wonder whether another sort of cap, like a polypropylene cap might be better?

[Richie]

Those are fine, 100v should also work fine, shouldn't be much and probably at the lower voltages is when it happens.
Dana has the info posted out there. And probably explain it better than i can.

Usually i'll mount these on a terminal strip. Look at the Dumble amps.
A small terminal strip mounted on or at the mounting screw/bolt of the tube socket. it makes an easy place to add those if modding or no place left on a board etc. The one lug that is bolted, can be used for the ground.

If you still have any dc or scratchy pots on the guitar or amp, i'd be doing some measuring. I don't know how many people have posted about leaky MICA caps. They have gotten so bad,many have quit using them.
If you use one for the treble cap and its leaky or bad, it can put quite a bit of dc on the amp pots. There are many other caps that could be used there or in place of the micas. And old micas don't seem to be bad. Just the new type ones. So for anyone using them, good luck.

And , the old saying, if its working now, sounds good, don't touch it!
Glad you got it working like it should.